The norris petebs co



Patented Feb. 28, I899.

G. B. PETSCHE. VALVE AGTUATING MECHANISM.

(Apfilication filed July 31, 1897.

2 Sheets-Sheet I.

(No Model.)

FIG

c li JYj Iriventor.

Witnesses. 76 ,1

A; Attdrney.

TNE NORRIS PEYERS co PHOTO-LITND.. WASHINGTON n. c.

Patented Feb. 28, I899.

GQB. PETSC'HE.

VALVE ACTUATING MECHANISM;

(Application am July :31, 1897.)

2 Sheets-Sheet 2.

(No Model.)

Invento1 4 WAT l.

I. Z. Attorney.

UNITED STATES PATENT OFFICE.

lrUSTAV BERNHARD PETSGHE, OF PHILADELPHIA, PENNSYLVANIA, AS- SIGNOR TOTHE SOUTHWARK FOUNDRY AND MACHINE COMPANY,

OF SAME PLACE.

VALVE-ACTUATING M ECHANISM.

SPECIFICATION forming part of Letters Patent No. 620,171, dated February28, 1899.

Application filed July 31, 1897. Serial No. 646,635. (No model.)

My invention relates to the construction of f mechanism for actuatingthe admission and 1 exhaust valves of steam-engines, and has for itsobject to provide a simple and efficient mechanism by which theadmission-valves may be operated with avvariable cut-off and constantlead and at the same time with un- 1 usual rapidity in opening andclosing and also to operate from the same controlling-link theexhaust-valves with constant release and compression and with the samequick action which I secure in the movement of the admission-valve.

The nature of my improvements will be best understood as described inconnection with the drawings in which they are illustrated, and in whichFigure 1 is a side elevation of a portion of a pumping-engine equippedwith my improvement, Figs. 1 and l being detached views of the admissionrock=cams, Figs. 1 and 1 similar views of the exhaust rock-cams, andFig. 1 an enlarged view showing a rock cam and lever in intermediateposition, Fig. 2 being a front elevation of the upper part; Fig. 3, aside elevation, on an enlarged scale, of the rock cams and leversforming an important feature of my construction; and Fig. 4, across-sectional view through the head of the engine, taken through theline 1 1 of Fig. 1.

A indicates the framing of the engine; B, the main shaft; 0, aneccentric on the shaft; and D a link which, as shown and as I prefer touse it, is familiarly known as the Finck link. The link is, as usual,provided with an eccentric-strap D, a slotted arm D and a pivotedconnecting-link D E is a block sliding in the arm D the position ofwhich is controlled in the usual mannor by a governor, (indicated at G.)

F is a point on the outer extremity of the slotted arm of the link, towhich connection is made for the actuation of the exhaustvalves of theengine, as will be hereinafter described.

I control the movements of the steam-admission valves of the engine byconnections from the sliding block E. Thus, as shown,

a link H extends from the said block to a rock-lever K, from whichextends a link H,

having in it adjusting screws H H as shown, and connecting with the armsI I of the rock-cams I and 'i, which are each made with an elevated faceI and depressed faces I I on each side of the elevated face andconnected therewith by symmetricalinclines, as shown. The two admissionrock-cams I and 2', operating as they do to open the admission-valves atthe opposite ends of the cylinder and both moving simultaneously in thesame direction, must have their cam-faces arranged differently and so asto operate their respective admission-valves in reverse directions. Theconformation of the cam-faces to efiect this purpose is indicated in thesmall cuts at the right-hand side of Fig. 1, in which l and 1 indicatethe rock-cams I and i, governing the admission, and 1 and 1 indicate therock-cams I and 17, having for their function the control of theexhaust-valves at the opposite ends of the cylinder, and,'as shown, theyare secured upon the same centers as the rock-cams I t' and are operatedthrough their arms I by a rod J which connects, as shown, through arock-lever K rod J, rocklever K, and rod J with the point F on the Fincklink. It will be understood, of course, that the rock-cams controllingthe exhaustvalves being simultaneously moved in the respective cams andare so spaced (see Fig. 1) that they will both remain at all times incontact with the face of the cam upon which they operate and so thatwhen one is elevated upon the upper cam-face the other will al ways bedepressed, resting upon one of the lower cam-faces. It is important thata close contact should be maintained at all times between the rollers ofthe rock-levers and the cam-faces, and, the spacing being carefullyadjusted to the length of the cam, it is only necessary to provide forthe wear of the surfaces, which can be readily done by making the pivotL, upon which the rock-lever turns, an adjustable eccentric or providingin other ways for setting it up toward the cam-face in case of wear.

M M indicate the valve-rods of the admission-valves, and N N thevalve-rods of the' exhaust-valves, said rods being connected to portionsL of the rock-levers, as indicated, and secured to the admission andexhaust valves (indicated at O and P in Fig. 4) in the usual manner.

Q indicates the livesteam pipe, Q the steam-chamber, and R theexhaust-chamber of the engine, the cylinder of which is indicated at S.

It will be understood that the throw of the eccentric B and theconnections therefrom to the valves are such that the said throw alonewill simply move the valve through their lap and lead, assuming that thesliding block E were situated immediately above the eccentric-that is tosay, coincident with the point of attachment of the swinging link 1) tothe link D. As the sliding block is moved out the rock-cams to which itis connected are moved through their longer arcs and agradually-increased admission of steam is provided for, the cut-offbeing proportionately delayed, at the same time an actual motion of thevalve is always effected with the same quickness, taking place, ofcourse, when the rock-lever changes its position on the face of the cam.A particular advantage incident to my construction is the utilization ofthe cam as a means of actuating the valve with entire avoidance of anyappreciable lost motion, the connection between the eccentric and thevalve being practically as positive as though all parts were actuallysecured together.

It will be obvious that the motion of the exhaust-valves will beentirely unaffected by the change in the position of the link slidingblock and will always take place at the same time, irrespective of thecut-off effected by the admission-valve.

The rock-cam and its coacting rock-lever is in itself, I believe, newwith me, and, as it is capable of many other uses than that indi-' catedin the above description and the drawings referred to, I have made itthe subjectmatter of a separate application for a patent, filed July 31,1897, Serial No. 646,632, my present invention being limited to its usein connection with and in the way illustrated and described with anoscillating link-motion and as a part of the mechanism for actuating theadmission or admission and exhaust valves of a steam-engine.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In an engine, the combination of avalvelink as D, actuated by theengine, a sliding block moving in said link and actuated by a governor,a rock-cam, as I, actuated by a connection from said block and having ahigh face I between two lower faces I I said high and low faces beingconnected by symmetrical slopes, a centrally-pivoted rock-lever L havingcam-contacting faces or rollers L L adapted to rest one on the high andthe other on the'low surface of the cam and to pass from high to low asspecified and a valve-actuating rod as M moving with the rock-lever.

2. In an engine the combination of a valvelink as D actuated by theengine, a sliding block moving in said link and actuated by a governor,two rock-cams I 't' actuated by a connection from said block and havinga high face 1 between two lower faces I I said high and low faces beingconnected by symmetrical slopes and said cams being setas described sothat when moved in the same direction they will actuate their coactingdevices in opposite directions, centrally-pivoted rock-levers L havingcam-contacting faces or rollers L L adapted to rest one on the high andthe other on the low surface of the cams and to pass from high to low asspecified and valve-actuating levers as M M moving with the rock-rods.

3. In an engine the combination of a valvelink as D actuated by theengine, a sliding block moving in said link and actuated by a governor,rock-cams as I I one connected to and actuated by the block in the linkand the other connected to and actuated by a fixed point on the linksaid cams having central high faces I with lower faces I I on each sideof it and said faces being connected by symmetrical inclines,centrally-pivoted rocklevers L L each having cam-contacting faces orrollers L L adapted to rest and work on the faces of the cams asspecified the one rocklever connecting to a steam-inlet valve and theother rock-lever to a corresponding exhaust-valve.

GUSTAV BERNIIARD IE'lSOllE.

Witnesses:

CHAS. F. MYERS, D. STEWART.

